Balloon angioplasty is routinely used to remove blockages in the tubular organs such as arteries or veins. In many clinical situations, blockages are hard solids, such as calcified plaque, and require the use of high pressures to dislodge such blockages. Commercially available high pressure balloons employ complex technology to achieve high pressure requirements without sacrificing the profile of the balloon. Besides high pressure requirements, the angioplasty balloons also must be resistant to puncture and scratch, easy to track and push, and present a low profile.
In clinical practice, angioplasty balloons are inflated using an X-ray contrast agent solution. Typically, a 70/30 percent mixture of contrast agent and saline is used to inflate the balloon during an angioplasty procedure. Some large volume balloons sometimes require up to 2 minutes of inflation/deflation times with the contrast agent. In general, there is need to reduce inflation and deflation times required for angioplasty balloons without sacrificing the profile of the balloons.
Because of its relatively high viscosity, there is also a need to eliminate or reduce the use of contrast agent used in inflation/deflation of the balloons. Saline solution can be used in inflation and deflation; however, it has zero visibility in X-ray imaging. The use of contrast agent increases the cost of the procedure, prolongs the inflation/deflation times and also poses the risk of iodine exposure to patients who are sensitive to iodine. There is a need for compositions and methods, wherein inflation and deflation of angioplasty balloons can be achieved without the use of X-ray contrast agent.
Furthermore, the physician performing the angioplasty procedure should be able to locate the position of the uninflated balloon with accuracy, so that the balloon will be properly positioned during and after inflation. This is conventionally accomplished by attaching marker bands on the catheter shaft in the region corresponding to the balloon body, which requires additional components to be added to the catheter. Care must also be exercised to position such markers properly, and to secure them to the shaft by, for example, adhesive bonding or crimping. All of this adds to the cost of the catheter. Furthermore, once inflated, the balloon is typically imaged using contrast media, as described above.
Accordingly, the need is identified for a balloon with radiopacity associated with the balloon itself, which would accurately reveal the position of the balloon before inflation, as well as during and after inflation.